2 papers
math.RA2024
Presentations for monoids of endomorphisms of a star graph
Vitor H. Fernandes, Jörg Koppitz, Tiwadee Musunthia
In this paper, we consider the monoids of all endomorphisms, of all weak endomorphisms, of all strong endomorphisms and of all strong weak endomorphisms of a star graph with a fini…
math.RA2019
The rank of the inverse semigroup of partial automorphisms on a finite fence
J. Koppitz, T. Musunthia
A fence is a particular partial order on a (finite) set, close to the linear order. In this paper, we calculate the rank of the semigroup of all order-preserving…